Electric furnace.



J. H. 1min.

ELECTRIC FURNACE. APPLICATION FILED DEC. 30, 190B.

Patented Apr. 13, 1909.

INVENTOR J. H. REID.

WITNESSES the accompanying specifications and UNITED STATES PATENT OFFICE.

JAMEs HENRY REID, OF NEvVAPtli, NEW JERSEY.

ELECTRIC FURNACE.

T all whom it may concern:

Specification of Letters Patent.

Application filed December 30, 1908.

Patented April 13, 1909.

Serial No. 470,105.

the space between the electrodes is filled in.

Be it known that 1, JAMES HENRY R211), by converging resistance elements K, L, M

of Newark, in the State of New Jersey, United States of America, have invented certain new and useful Improvements in Electric Furnaces, of which the following is a specification.

My invention relates to improvements in electric furnaces, and the ob,ects of my invention are to provide an exceedingly simple and effective form of furnace for refining ore,

particularly ores containing a large quantity of silica or slag, and such a furnace as will carry out the refining process in the most economical manner possible.

' 1n carrying out the construction of the furnace, a treating table is formed by a plurality of converging electrodes, and resistance elements having perforations therethrough, through which the melted metal may drop, in combination with means for spreading the ore to be treated on the table, and clearing it off of the same.

All these and other features of the invention are more fully set forth and described in drawings.

In the drawings, Figure 1. is a vertical section'through the furnace. Fig. 2 is a horizontal section on the line 2-2, Fig. 1.

In the drawings, like characters of reference indicate corresponding parts in each figure.

Referring to the drawings, A represents the outer casing of the furnace of suitable construction provided with-an open bottom. Nithin this outer casing a central chamber B is provided formed with a smaller casing C lined with suitable fire brick 10, and having a bottom 11 with a discharge hopper 12 adapted to discharge into a suitable receptacle or pit D.

Both furnaces are preferably made circular in horizontal section, but it is evident that the shape may be varied to suit the circumstanccs. The heating of the furnace is accomplished through a plurality of converging electrodcs E, F, G and ll,- and these, in :wcordancc with the present invention, extend substantially horizontal and rest on the top of the inner chamber I meeting at the center thereof. Each of the electrodes may be provided with suitable constant current regulators I, such as that described in detail in my earlier application Serial No.

449877, filed August 22nd, 1908.

The top of the chamber B is left open and I. l l

hereinafter described.

and N, which also extend horizontally through the outer casing A, and may be forced inwardly by suitable means, as by springs 13 supported from frames 14 secured to the side of the furnace, and normally pressing the resistance elements inwardly.

The ends of the electrodes and the, resistance elements which extend above the open top.of the chamber 13 are provided with a plurality of perforations 15, of such size as to prevent the ore normally passing therethrough, but to permit the metal in its molten state to pass through into the chamber 13.

The width of the resistance elements is such that they, together with the electrodes,

will cover the entire top of the chamber, B, and it will thus beseen that they, together, with --the electrodes, form substantially a table on which the ore may rest during treatment.

The ore to be treated may be introduced on to the table through suitable hoppers 16 and 17, in the top of the casing A, and to spread it out evenly on the table a sweep O is provided, including a vertically-extending shaft 18 hav ng a collar 19 thereon which rests on the top of a bearing 20 in the casing, and being provided with a pulley 21 by means of which it may be rotated and a sweeping arm 22 at the bottom of the shaft radially extending in the furnace, and having a facing 23 of fire bricks or other refractory -material. The lower edge of the sweeping arm 22 extends parallel with the table formed by the resistance elements and electrodes, and its height above the table may be adjusted by adjusting the colla1f19 on the shaft 18, the said collar being heldin any adjusted position by meansof suitable set-screws 24 Below the annular space between the chamber B and the outer casing A, 'anannular trough P is providedadapted to receive the slag as it drops from off the table as To withdraw the volatile products from the casing A, an outletpipe may be provided.

In using the furnace, the ore to be treated is introduced through the hoppers 1'6 and 17 on to the top of the table formed by the resistance elements and electrodes. The sweep O is then adjusted so that the arm 22 is a few inches above the table and,the shaft 18 is applied and arcs will be produced both between the electrodes and between the electrodes and resistance elements, and the latter will also be heated by the passage of current therethrough. This heating of the ore by both the electric'arc and resistance elements will melt the metallic portion of the same, which will pass through the perforations 15 and drop into the receptacle or pit D.

If desired, in order to facilitate the reduction of the ore any suitable or necessary reagents -may be introduced through the hoppers 16 and 17.

As soon as all the metallic constituents are freed from the ore, or as soon as the reduction is deemed complete, the sweep is lowered until the lower edge thereof just touches the upper surface of the resistance elements and e ectrodes and is again rotated. This will sweep the residue of the ore, Which will be mainly the silica or slag, off the table and these will drop through the annular space 26 into the tank or receptacle P, and may then be withdrawn or used as desired.

The furnace will be found very useful for treating ores containing small quantities of valuable metals, such as low grade silver or gold ores, but its application is evidently possible to the treating of a great variety of other ores. 1

.t will be observed that While a plurality of perforations are illustrated extending through the electrodes and resistance elements, yet, these may be dispensed with as the spaces between the electrodes and the resistance elements will usually be sufficient to permit the melted ore to pass out It will also be evident that ifdesired the outer casing might be varied in construction or possiblyrdispensed with. .3

As many changes could be made in the above construction, and many apparently widely different embodiments of my invention, within the scope of the claims, couldbe made, without departing from the spirit or scope thereof, it is intended that .all matter contained in these specifications and drawings, shall be interpreted as illustrative and not in a limiting sense.

What I claim as my invention is 1. An electric furnace having a plurality of converging electrodes of different polarity and adapted to produce arcs between, in combination with means for spreading the ore on the electrodes.

2. An electric furnace having a plurality of horizontally extending electrodes of different polarity adapted to constitute a table within the furnace and to produce arcs becasing, an inner chamber having an open top,

a plurality of electrodes extending over the inner chamber, and having perforations through which the'ore may pass, and means for spreading the ore onthe electrodes.

5. An electric furnace comprising an outer casing, an inner chamber having an open' top, a plurality of electrodes, and resistance elements forming the top of said chamber, and having perforations therethrough' through which the melted metal may ass. v

6. In an electric furnace, t e combination with a chamber, of a plurality of electrodes extending over the same having perforations throu h which the melted ore may pass.

7. l n an electric furnace, the combination with a chamber having an open top, of a plurality of electrodes, and resistance elements covering the top and-having passages ways through which the melted ore may dro 8 An electric furnace including an outer casing, an inner smaller chamber formed with an open top, a plurality of resistance elements and electrodes constituting the top of the inner chamber, and an adjustable sweep operative above the said resistance elements and electrodes.

9. An electric furnace, including an outer casing, an inner chamber having an open top, a plurality of converging electrodes and resistance elements, constituting the top of the said chamber, and having passage-Ways through which the ore may pass, and a vertically-adjustable sweep operative above said resistance elements and electrodes, and adapted both to. spread the ore on the same and sweep it off,

.10. In an electric furnace, a plurality of converging electrodes of different polaritieshorizontally disposed and forming a table to receive the. ore and being adapted to produce arcs between.

In witness whereof I haye hereunto set my hand in the presence of two witnesses.

JAMES HENRY REID.

VVitne'sses RUssEL D. SMART. W'M. A. lVYnAx'. 

